class ActiveModel::Type::Date

are cast using their to_date method, if it exists.
String values are parsed using the ISO 8601 date format. Any other values
person.birthday.day # => 13
person.birthday.month # => 7
person.birthday.year # => 1989
person.birthday.class # => Date
person.birthday = “1989-07-13”
person = Person.new
end
attribute :birthday, :date
include ActiveModel::Attributes
class Person
:date key.
Attribute type for date representation. It is registered under the
= Active Model Date Type

def cast_value(value) 

def cast_value(value)
  if value.is_a?(::String)
    return if value.empty?
    fast_string_to_date(value) || fallback_string_to_date(value)
  elsif value.respond_to?(:to_date)
    value.to_date
  else
    value
  end
end

def fallback_string_to_date(string) 

def fallback_string_to_date(string)
  parts = begin
    ::Date._parse(string, false)
  rescue ArgumentError
  end
  new_date(*parts.values_at(:year, :mon, :mday)) if parts
end

def fast_string_to_date(string) 

def fast_string_to_date(string)
  if string =~ ISO_DATE
    new_date $1.to_i, $2.to_i, $3.to_i
  end
end

def new_date(year, mon, mday) 

def new_date(year, mon, mday)
  unless year.nil? || (year == 0 && mon == 0 && mday == 0)
    ::Date.new(year, mon, mday) rescue nil
  end
end

def type 

def type
  :date
end

def type_cast_for_schema(value) 

def type_cast_for_schema(value)
  value.to_fs(:db).inspect
end

def value_from_multiparameter_assignment(*) 

def value_from_multiparameter_assignment(*)
  time = super
  time && new_date(time.year, time.mon, time.mday)
end